出典:Wiktionary
出典:『Wiktionary』 (2025/05/17 14:03 UTC 版)
interstellar cloud (plural interstellar clouds)
出典:Wikipedia
出典:『Wikipedia』 (2011/05/20 03:43 UTC 版)
Interstellar cloud is the generic name given to an accumulation of gas, plasma and dust in our and other galaxies. Put differently, an interstellar cloud is a denser-than-average region of the interstellar medium. Depending on the density, size and temperature of a given cloud, the hydrogen in it can be neutral (H I regions), ionized (H II regions) (i.e. a plasma), or molecular (molecular clouds). Neutral and ionized clouds are sometimes also called diffuse clouds, while molecular clouds are sometimes also referred to as dense clouds.